Hello Aspirant...

As it is only a mock seat allotment it's results will not give as equal as original seat allotment because actual seat allotment has some reasons that you can get other college like

some students don't take admission after the seat allotment,

You can go upto last round of counselling as there are many rounds in josaa so in that case if students don't show up to the college in next round you might get that seat if your rank is good.

You can go through previous year cutoffs in below article for NITs

https://engineering.careers360.com/articles/nits-cutoff-for-top-btech-branches

All the best